Las Orquideas de El Salvador Vol. 1, Vol. 2 & Vol. 3

Text is in English, Spanish, and German.

Volume 1 & 2 - written in 1974 - describes 279 species in 67 genera, with comments on a further 41 species in the apendix.  -  267 colour photographs and 265 line drawings and index. 

Volume 3 - written 1981 describes 84 additional species in 49 genera, not previously recorded. 67 colour  photographs; 132 line drawings and index.

The 3 volume set of this title is rarely offered for sale.